1. Field of the Invention
This invention relates to a closure for a container with a lower closure element and a closure cap which can be placed on the lower closure element. The lower closure element is connected to the opening of a container by a base element having a contact flange which rests against the inner wall of the container against a contact face formed in the area of the opening of the container. One or more locking projections are disposed on the base element in the axial direction of the container closure and at a distance from the contact flange. The locking projections extend over the rim of the opening, so that the lower closure element is held axially immovable in the container.
2. Description of Prior Art
Generally, closures of the type described above are employed for containers which are filled with a substance under pressure. The contact flange is pressed against the contact face because of the pressure difference with the atmosphere surrounding the container, so that the container closure cannot be pushed out of the opening. A container closure of this type is taught by German Patent Publication DE 38 32 412 A.
Locking projections which extend over the opening of the container are provided on the base element for the axial fixation of the container closure. The base element is thus clamped between the locking projections and the contact flange of the portion of the container facing the opening. If a force is applied to such a container closure in the direction of the circumference of the closure cap, for example when a screw cap is unscrewed or removed, the base element rotates in the opening.